Neurodegenerative diseases such as Parkinson's disease, Lewy body dementia and Huntington's disease affect millions of individuals. Parkinson's disease is a chronic, progressive motor system disorder that afflicts approximately one out of every 1000 people, with hereditary Parkinson's disease accounting for 5-10% of all of patients. Parkinson's disease is caused by progressive loss of mid-brain dopamine neurons, leaving patients with impaired ability to direct and control their movements. The primary Parkinson's disease symptoms are trembling, rigidity, slowness of movement, and impaired balance. Many Parkinson's disease patients also experience other symptoms such as emotional changes, memory loss, speech problems, and sleeping disorders.
The gene encoding the leucine-rich repeat kinase 2 protein (LRRK2) has been identified in association with hereditary Parkinson's disease (Paisan-Ruiz et al., Neuron, Vol. 44(4), 2004, pp 595-600; Zimprich et al., Neuron, Vol. 44(4), 2004, 601-607). In-vitro studies show that Parkinson's disease-associated mutation leads to increased LRRK2 kinase activity and decreased rate of GTP hydrolysis compared to wild-type (Guo et al., Experimental Cell Research, Vol. 313(16), 2007, pp. 3658-3670. Anti-LRRK2 antibodies have been used to label brainstem Lewy bodies associated with Parkinson's disease and cortical antibodies associated with Lewis body dementia suggesting that LRRK2 may play an important role in Lewie body formation and pathogenesis associated with these diseases (Zhou et al., Molecular Degeneration, 2006, 1:17 doi:10.1186/1750-1326-1-17). LRRK2 has also been identified as a gene potentially associated with increased susceptibility to Crohn's disease and susceptibility to leprosy (Zhang et al., New England J. Med. Vol. 361 (2009) pp. 2609-2618.
LRRK2 has also been associated with the transition of mild cognitive impairment to Alzheimer's disease (WO2007/149789); L-Dopa induced dyskinesia (Hurley et al., Eur. J. Neurosci., Vol. 26, 2007, pp. 171-177; CNS disorders associated with neuronal progenitor differentiation (Milosevic et al., Neurodegen., Vol. 4, 2009, p. 25); cancers such as kidney, breast, prostate, blood and lung cancers and acute myelogenous leukemia (WO2011/038572); papillary renal and thyroid carcinomas (Looyenga et al., www.pnas.org/cgi/doi/10.1073/pnas.1012500108); multiple myeloma (Chapman et al., Nature Vol. 471, 2011, pp. 467-472); amyotrophic lateral sclerosis (Shtilbans et al., Amyotrophic Lateral Sclerosis “Early Online 2011, pp. 1-7); rheumatoid arthritis (Nakamura et al., DNA Res. Vol. 13(4), 2006, pp. 169-183); and ankylosing spondylytis (Danoy et al., PLoS Genetics, Vol. 6(12), 2010, e1001195, pp. 1-5).
Accordingly, compounds and compositions effective at modulating LRRK2 activity and usable as PET ligands may help in developing and providing treatment for neurodegenerative diseases such as Parkinson's disease and Lewie body dementia, for CNS disorders such as Alzheimer's disease and L-Dopa induced dyskinesia, for cancers such as kidney, breast, prostate, blood, papillary and lung cancers, acute myelogenous leukemia and multiple myeloma, and for inflammatory diseases such as leprosy, Crohn's disease, amyotrophic lateral sclerosis, rheumatoid arthritis, and ankylosing spondylytis.